A contraction is a shortened form of one or two words (one of which is usually a verb). In a contraction, an apostrophe takes the place of the missing letter or letters. Some contractions are: I'm (I am), can't (cannot), how's (how is), and Ma'am (Madam).

For example, "don't" is a contraction that is short for "do not"; the apostrophe in "don't" takes the place of the missing "o". Another example is "o'clock," a contraction "of the clock." A less common example of a contraction is "jack-o'-lantern," short for "jack-of-lantern"; in it, the apostrophe takes the place of the missing "f" in "of."